Remove redundant typedef
Remove redundant typedef

$ git grep -n "typedef struct LibDwSession_ "
rts/Libdw.c:63:typedef struct LibDwSession_ LibDwSession;
rts/Libdw.h:22:typedef struct LibDwSession_ LibDwSession;

This trips up (e.g.) GCC v4.4.7.

gridaphobe/ghc,tjakway/ghcjvm,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,sdiehl/ghc,tjakway/ghcjvm,AlexanderPankiv/ghc,shlevy/ghc,olsner/ghc,snoyberg/ghc,GaloisInc/halvm-ghc,elieux/ghc,nushio3/ghc,sgillespie/ghc,oldmanmike/ghc,shlevy/ghc,nushio3/ghc,sgillespie/ghc,oldmanmike/ghc,elieux/ghc,elieux/ghc,vTurbine/ghc,vikraman/ghc,tjakway/ghcjvm,sdiehl/ghc,oldmanmike/ghc,mcschroeder/ghc,AlexanderPankiv/ghc,da-x/ghc,elieux/ghc,gridaphobe/ghc,sgillespie/ghc,vikraman/ghc,mcschroeder/ghc,snoyberg/ghc,mcschroeder/ghc,sgillespie/ghc,AlexanderPankiv/ghc,nushio3/ghc,gridaphobe/ghc,snoyberg/ghc,olsner/ghc,da-x/ghc,shlevy/ghc,GaloisInc/halvm-ghc,gridaphobe/ghc,ezyang/ghc,vTurbine/ghc,oldmanmike/ghc,snoyberg/ghc,vTurbine/ghc,mettekou/ghc,ezyang/ghc,sgillespie/ghc,mettekou/ghc,sgillespie/ghc,mettekou/ghc,nushio3/ghc,GaloisInc/halvm-ghc,ezyang/ghc,nushio3/ghc,GaloisInc/halvm-ghc,mettekou/ghc,snoyberg/ghc,GaloisInc/halvm-ghc,AlexanderPankiv/ghc,vikraman/ghc,da-x/ghc,gridaphobe/ghc,sdiehl/ghc,oldmanmike/ghc,olsner/ghc,tjakway/ghcjvm,gridaphobe/ghc,sdiehl/ghc,tjakway/ghcjvm,ezyang/ghc,oldmanmike/ghc,da-x/ghc,vTurbine/ghc,mettekou/ghc,mettekou/ghc,sdiehl/ghc,elieux/ghc,AlexanderPankiv/ghc,oldmanmike/ghc,shlevy/ghc,nushio3/ghc,sdiehl/ghc,gridaphobe/ghc,olsner/ghc,AlexanderPankiv/ghc,elieux/ghc,olsner/ghc,tjakway/ghcjvm,mettekou/ghc,vTurbine/ghc,shlevy/ghc,vTurbine/ghc,snoyberg/ghc,ezyang/ghc,sdiehl/ghc,shlevy/ghc,olsner/ghc,elieux/ghc,shlevy/ghc,sgillespie/ghc,ezyang/ghc,da-x/ghc,mcschroeder/ghc,mcschroeder/ghc,AlexanderPankiv/ghc,ezyang/ghc,mcschroeder/ghc,mcschroeder/ghc,nushio3/ghc,vikraman/ghc,da-x/ghc,da-x/ghc,tjakway/ghcjvm,vikraman/ghc,olsner/ghc,vikraman/ghc,vikraman/ghc,vTurbine/ghc,snoyberg/ghc